I have a new-to-me Yugo 24/47 in 8mm mauser. The rifle is in excellent condition with matching numbers. I also have a couple hundred rounds of 7mm mauser standard pressure factory loads. A few questions...

Is is safe to shoot the 7mm mauser rounds in the 8mm mauser rifle to obtain 8mm mauser reloadable brass? If it is safe, is it likely to cause a lot of copper fouling in the rifle?

If it is not safe, can I pull the 7mm bullet and leave the factory charge and use some type of plug in the neck case to create enough back pressure to fireform the case? What should I use for the plug?

Many thanks.

<>< Brian

Headspace! Don't do it. Got any 06 brass?
If not, head to your local sighting in area and pick up some from the guys who hunt but don't reload. Size in 8x57 die and trim. If you are new to 8mm...good cartridge. 4895 to 4350 works great.
If you want to use the 7mm, pull the bullets and resize in at least 2 steps. Notice the 7mm shoulder is shorter than the 8mm. You will have to create another shoulder for the final case.
Bill

Thanks Wahoo.

Didn't think of the 30-06 brass. That sounds like the way to go for me.

<>< Brian

Run the 7 X 57 brass over expanders up to .338, then pass it through the 8 X 57 die before fireforming. On the other hand, 8 X 57 brass isn't expensive. Just call Midway and be done with it.

I already have a small batch of brass in the mail.

I just wanted to see if there's a good use for the 7x57 ammo and brass I have laying around.

Thanks for the specifics on expanding the brass.

8x57 brass is the way to go.

I would suggest you buy a rifle to fire that 7x57 ammo in next hunting season.

JW

Aussie,

That's how all of this came about. I am a Ruger #1 fan that had a 1A in 7x57mm that I couldn't get to shoot well.

Through a series of trades and buys I now have a 300 H&H and a 375 H&H. I'm quite happy with this pair.

The 8mm mauser belongs to my son. He's really into classic military rifles.

I tried selling my 7x57 ammo locally. Just not much demand for it.

<>< Brian

You can seat the bullets out to touch the lands and fireform 7x57s to 8x57s. I have fireformed a lot to them this way...I also know a bunch of Africans that just shoot up tons of free 7x57s in there 8x57s to get the brass and they are all still alive, I know folks that have been shooting .270s in the 06 or 30-06's in their 338-06s and 35 Whelans. I never much like the idea of a 30 caliber bullet rattling down my bore but it doesn't seem to hurt anything and a great smith once told me copper and lead is softer than steel so why would it hurt......folks have been doing all of these things for ions against sage advise..???????? I always wondered where that advise came from and what it was based on? is it some gunscribes gem of wisdom or does it really have substance and is it based on proven fact. I know of nobody that has ever been injured by this practice..'

I don't know the answer but it would not bother me to fireform in the above calibers. However I don't mess with fireforming anymore, too many good calibers out there and brass ain't that expensive unless you shoot a lot more than I do...

Does a .284 bullet touch .315 lands? Is there a typo here?
Remember 7mm and 8mm don't headspace the same.
Do you mean expand and seat 8mm bullets seated to touch the lands?
Bill

Could you use a 7.62 expander ball in the 8 mm die, then go with an 8mm expander ball? I've never gone this much before on expansion, but seems if you anneal the necks of the 7mm and go up in steps, it might work?

Huh?

Ray,

Will you please elaborate on your post? Are you saying that the 7mm bullet in the 7x57 case must be touching the lands in order to keep the case from stretching too much when the its fired? I think that the diameter of the 7mm bullet would prevent this from being possible.

I value your opinion on this. I just don't want to do something unsafe because others have gotten away with it.

<>< Brian

I've got a good use for it if you were going to throw it away

Perhaps someone will respond to help me further my education on this subject...

My understanding is that when a beltless and rimless case with a shoulder that is too short for the chamber is fired, the case drives forward from the blow of the firing pin, ignition occurs, the case expands to the chamber walls while temporarily sticking to the them and the case then begins to elongate backwards toward the bolt face. This can be a primary cause of case head separation when the tolerances are too great.

If this is true then what would happen in the following scenario with a 7x57 in a 8x57 chamber? You are using a CRF bolt that captures the case with very little slop. You fire a case that has practically the same dimensions except the shoulder is about 0.01" short. Wouldn't the case flow forward primarily in the shoulder and neck area because the rim is captured by the CRF bolt?

This may explain Ray's experiences with this particular setup.

Thanks for your time in dicussing this.

<>< Brian

(edited for spelling)

I've never tried firing 7mm in an 8mm chamber. I suspect it would be a good test of gas handling properties.
Everything I think I know about guns says this would lead to a good story, hopefully w/o injury.
When buying military rifles for $15 at K-Mart was a big deal, we would test them, after cleaning out the bore, by tying them in a fixture with the butt against a tree and a string on the trigger. If you didn't have trouble, we proceeded to cut them down into sporters!
Bill

Mtngoat,
My bad, I ment if you expand the 7x57 neck to accept a 8mm bullet it is recommended that the bullet should make contact with the lands or be very close when fireforming to get a full fireform or so is the accepted therory.....sorry, and thanks for the heads up. However I have fireformed many 30-06 with cormeal, Unique pistol powder, and a wax gob or stuffed a Kleenex piece over the powder charge to fireform a case.

As to the other, I have shot a few 30-06s in a 35 Whelan to fireform the case, and never had a problem. This was a very common practice back in the early days and I never heard of an accident in doing so.. Like I said in my previous post, I have watched some African sit and shoot many 7x57s in there 8x57 Mausers with no harm at all. I think perhaps "like cartridge cases" may be the antedote in that your not moving the shoulder, your just expanding the neck in both instances..

I have seen folks shoot .270s in their 30-06s..I was with a guy that shot up 3 boxes of 270s in his 30-06 at Antelope and never hit one, I finally gave him my gun and he killed the next one he saw, then I looked at his rifle and while unloading it I noticed the cartridges were .270s, bingo! problem solved, he had grabbed the wrong ammo. He had sold his .270 some months prior. Again your just expanding the neck, and not moving the shoulder.

There are instances where you can get into trouble for sure, such as shooting a 243 in a 257 or someting like that..I had a ranch hand that fired a 250 Sav. in my .243 Savage 99F that he borrowed..It locked up the gun and took a piece of pipe and hammer to open it. He said it really kicked the snot out of him, but no harm..It sprung the lever, but I did repair it..That was a close one I suspect, as it had to swedge a 257 caliber bullet to .243, no damn wonder it kicked...:)

Keep in mind that when you fire a 30-06 in a 35 Whelan chamber you have less pressure than you will have firing a 35 caliber down the barrel, and the cases are the same, all your doing is expanding the neck, same with the 7x57. You are not moving the shoulder forward and this is the key as I said above.!!!..

I never particularly liked the idea of a the smaller diameter bullet rattling down the barrel even if copper/lead is softer than steel, but it has never harmed any bores that I know of...

I am not talking about therory, I am talking about what has been done pretty regular over the years and has been accepted in some circles I suppose, at least as long as I can remember.. Many of you are talking about what you think could happen, and that may or may not be correct.

I don't reccommend anything, it's all I can do to take care of myself, so I am just passing on some things I have seen, done, or know have taken place for for a long time for what ever its worth one way or another..

Thanks for clearing that up for me. I much prefer experience to theory!

The 270 and 35 Whelen have the same headspace dimension as the 06.
The 7mm is shorter (shoulder) than the 8mm.
Bill

Wahoo,

I realize that the 7x57 shoulder is about 0.01" of an inch shorter than the 8x57. I stated that in a prior post.

I am not advocating doing what I mentioned in the title of this thread. I am just trying to learn something here. I guess the real question is how far can a case shoulder safely move forward by fireforming? I know there are a lot of variables involved.

Perhaps I shouldn't have even asked the question.

Thank you for all of your input.

<>< Brian

(edited for spelling)

Picture of the 57mm family

nice picture. Looks like the 8 came first, and they didn't want anybody trying to shoot an 8 in a 7 chamber? So they made the 7 chamber (shoulder) shorter than an 8, so that an 8 would never chamber in a 7?

The 8 did come first, right?

Sycamore

If you size '06 in an 8x57 die you'll have to remove the decapping assembly to get a properly trimable case in most instances....then resize with the decapping assembly in place afterwards to get the neck interior right.
If you're going to do a lot of '06 to 8x57,you may be better off to by an 8x57 trim die.....makes the form/trim process much simpler and quicker,and you can literally do thousands with no wear on the die.

8x57-1888
7x57-1892

Wahoo,
I also realize the 7mm is a tad shorter, but very little and by using your therory on that, consider the fact that many factory and custom chambers are too long for factory ammo by one degree or another, and they fireform to the specific chamber when fired. I am sure that most have noticed that..

That is the reason we set our reloading dies up on a once fired case by using a full length die and running it into the die a tad at a time until we get the fabled crush fit for bench rest, target and some use this for hunting and others go just a tad more for hunting as they feel dependability rates higher than the little bit of accuracy that may or may not be gained by a crush fit.

When you fireform a case with cornmeal and wax your once again pushing the shoulder forward as you must, that is why it is wise to point the gun up when fireforming so the primer will stay back as the shoulder goes forward, not to hold the powder in the back of the case as some think, the cornmeal or rice does that..The pressue of the powder will push the case back if pointed up.

I think it was Bob that said I probably used a control feed rifle and he is correct about that. That applied in each case I sighted btw such as the Africans as they were using milsurp Mausers. The fellow that shot the 270s in his 06 was also using a pre 64 Win. I was using Mausers and pre 64s as most know that is about all I shoot in bolt action big game rifles, with the one exception of my Sako L-461 in a 6x45..I also shoot some Remingtons in varmint calibers.

You always read that when looking at an old rifle, to have a gunsmith check it for safety. I've never thought about this this way but...how much headspace over the 'spec' is permissable? I've never fooled around with gauges and the only gun I've had with excess headspace was an old Mod 12.

When all the old military stuff was being sporterized back when, I'm sure there were a lot of examples of 'gunsmithing' that put the actions to the test. Probably not so much of a problem these days. People seem more careful.
Bill

Even today the old Win. M-94 and a few others will show some headspace on firing if you will look at the primers and see how much they back out...Dennis Olson told me most of them back out about .004 to as much as .005 and don't cause any problems in the weak 94 action. My 25-35 leaks about .002 or .003 every shot, (guessing)...

I post that for what its worth and I don't know the real answer to the question of how much is too much. I am sure it would depend on the action in that I think the Ruger No. 1 could take a lot more than a Win. 94 or any bolt action.

A freaking 7x57 is .093" shorter at a smaller diameter shoulder than the 8x57... Suggesting it is okay to shoot factory or military ammo in one is just another headshaker! Should they point them "up" also? Do not want to ruin the brass, you know!

Unreal!
art

Headspace is mis-understood by so many for so many reasons it isn't even funny...if you have to ask the question or can't understand the full ramifications of what you can and can't do as far as correcting headspace and what it really is, you need to do more studying...NOT ON THE WEB FORUMS...as all you will get is you more mis-information and wrong answers...you need to go to an authoritive source like SAAMI.

85% of all the people I ever talked to about headspace couldn't understand the simple concept of using a standard sizing die and Redding competition shell holders to "adjust and correct" headspace...or the concept of "Go, NoGo, Field and War" headspace gauges.

SAAMI headpace is a "standard" used by all signatories of the SAAMI convention and as signatories they pledge to stay within the parameters set by that convention...this means ammo and component producers, reamer makers, barrel makers..the whole shebang.

AND...just because it is "old military stuff" doesn't mean the headspace is out...but it does mean that...LIKE ANY USED WEAPON...the headspace and ALL THE REST OF THE WORKING PIECES AND PARTS need to be checked over it you are smart.

Many people miss the fact that manufacturing methods require a certain level of TOLERANCE built in to keep things in perspective...nothing is made to exact specs...and many people get "tolerance" and "headspace" mixed up in their minds and other places.

Many SAAMI specs I've come across doing my own "gunsmithing" runs to about 0.000" - 0.008" range...BUT...If you want to know the specific SAAMI spec for a specific cartridge...go to SAAMI or a qualified gunsmith...NOT THE WEB...if you want the correct information and not a bunch of "personal guestimation BS".

There are correct ways of fireforming cases and correct ways of making different size cases and calibers from other size cases and incorrect ways of doing the same...again you need to be sure of your source. P.O. ACKLEY's books have the correct way and that way has been repeated countless times over the years. This isn't rocket science...it just had a right and wrong way to go about doint it.

But before you start you need to understand...FULLY...the concept of headspace...what it is...how it is applied...and how you approach it with differenct receiver types.

I've made all kinds of cases for "standards" and wildcats from whatever I happen to have stuck away on the brass shelf...if I can do it...SAFELY...any one can...

THE question that remains is...HOW you identify a modified case and HOW you mark it so you don't breakout in azz***es and sh** all over youself and really mess up your day.

Is the economy that bad ? No 7's thru My 8, no way. While I'm thinking of it, No 708's thru My 308's, either.

Certainly one way to get brass would be to collect as much .30-06 brass as you can, run them through a case tumbler, then carefully lube the top 1/3 of the case with a good case lubricant, then run the case into an adjusted 8x57 trim die, use a hacksaw to cut of the excess, then using a tray of tap water line up the cases base down and apply heat from a propane torch to anneal the necks, run them all through a full-length sizing die, trim to length, inside chamfer and then outside chamfer the case mouths, inspect carefully and then decide to get a life.

Call Midway.

Been there and done that. Back in the early 1970's it was tough getting components because everything was tied up in production for the Viet Nam War. 7x57 cases were just about about impossible to get and I had lots and lots of GI military .30-06 brass. It's a simple process really, but time consuming. There is really no need to go through all that when 8x57 cases are so easy to get.

I have had an 8mm of some kind since '65. Good cartridge which doesn't get any respect. For some reason 8mm unprimed brass is much more expensive than more common calibers.
This made forming a practical solution. A recent price check put 8mm brass twice as expensive as 06 brass. With 06 commonly available from hunters...it's everywhere shooters gather. 06 brass is the best starting point.

The process isn't complicated and there are several ways to do it, as has been posted.

I hope the late availability of Mausers brings more interest but american hunters aren't very interested in anything above 30 cal.
8mm was very popular in the 50's and 60's simply because the rifles were cheap, and not many had the extra cash to use the kind of rifles common to users of this forum. I knew more than a few successful hunters who did nothing more than clean and strip excessive hardware off a '98 cutting down the forend some, then head to the woods!
You can kill whitetails with a German rifle even if it doesn't have a German scope on it.
Bill

If you want to spend the time and hacksaw away to save $4 per 100 theses days I'm all for it.

Some prices from PVI Not quite double.

30-06 SPRINGFIELD - PER 50 Yes $18.50

8MM MAUSER (50) Out of Stock $22.12

I think 'out of stock' may be more relevant. It's good to see that the economy isn't a problem here! Finding green shoots coming out of the ground means we're closer to recovery than I had suspected.
Rather than spend and wait....and having 06 available...and this really isn't that hard.
Bill

I decided a few days ago not to pursue this avenue, even though others have gotten away with it.

Thanks for all of the input. I've learned alot.

<>< Brian

Taking the advice of one of the prior posters I looked up some info on the SAAMI site. The combination I asked about was on their "Don't Do This" List.

I tried posting the list here but the format was cumbersome.

Try this link if you are interested.

http://www.saami.org/Unsafe_Combinations.cfm

(edited for sp.)